All,
I was quickly going through this document:
http://www.w3.org/MarkUp/Forms/wiki/The_XForms_Transform_Function_Module
I don't remember if we discussed in the working group supporting
storing the transform (stylesheet) in an instance in addition, in
other words to also allow:
Object transform(node, node?)
where the first parameter points to the transform.
The same type of dependency tracking that can be used for the input of
the transformation can also be used to detect whether the stylesheet
itself has changed.
In most use cases, I would imagine the transform to be stored in its
own instance and rarely modified, therefore allowing an implementation
to cache the compiled transform efficiently.
-Erik